The following recommendations should be followed for ALL patients started on warfarin:
The risks of COUMADIN therapy may be INCREASED with the following:
Geriatric Use: Patients 60 years or older appear to exhibit greater than expected INR response to the anticoagulant effects of warfarin. COUMADIN is contraindicated in any unsupervised patient with senility. Observe caution with administration of COUMADIN to elderly patients in any situation or with any physical condition where added risk of hemorrhage is present. Consider lower initiation and maintenance doses of COUMADIN in elderly patients.
A] Assess bleeding risk: check all that apply:
C] Select NOMOGRAM:
Standard nomogram – 5mg initial dose. Bleeding risk: LOW.
High-risk nomogram – 3mg initial dose. Bleeding risk: HIGH.
High-risk nomogram – 2.5mg initial dose. Bleeding risk: HIGH.
High-Intermediate dose nomogram – 7.5–10mg -Bleeding risk: LOW
(Custom) Warfarin INITIATION nomogram– (INPATIENT)
(Custom) Warfarin INITIATION nomogram– (OUTPATIENT)
Note: If a custom
nomogram is selected please select the
(Starting dose should be based on patient age; presence of interacting
and bleeding risk of patient.)
Baseline INR and CBC should be obtained prior to initiation of warfarin therapy.
nomograms are based on INR values obtained daily in order to
predict/determine the maintenance dose requirements.] Once a
patient stabilized (two therapeutic levels 24 hours apart), follow-up
monitoring should occur approximately weekly for the first month (initiation
regimen for most patients unless factors are present that may significantly
increase or decrease the response to warfarin. Using higher doses e.g.
7.5 to 10mg for an average patient with no known risk factors for bleeding
is more likely to result in overanticoagulation.
who are at an increased risk of bleeding such as the elderly (> 70-75) or
patients with CHF/ liver disease / debilitated / recent major surgery /
nutritional intake/ or patients receiving medications known to potentiate
the action of warfarin (e.g. amiodarone or similar medications). Increased
patients with a LOW risk of bleeding, especially if very large; receiving
medications known to decrease the response to warfarin; concurrent
medical condition(s) such as clinical hypothyroidism that may reduce
response to warfarin. In selected patients (e.g., very large
individuals or those on medications known to antagonize warfarin), a Day 1
warfarin dose of 7.5 mg may be appropriate.